GNUPG-1-9-BRANCH gnupg/agent (command-ssh.c)
cvs user mo
cvs at cvs.gnupg.org
Wed Jan 26 23:17:01 CET 2005
Date: Wednesday, January 26, 2005 @ 23:25:36
Author: mo
Path: /cvs/gnupg/gnupg/agent
Tag: GNUPG-1-9-BRANCH
Added: command-ssh.c
added missing file
---------------+
command-ssh.c | 2327 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 2327 insertions(+)
Index: gnupg/agent/command-ssh.c
diff -u /dev/null gnupg/agent/command-ssh.c:1.1.4.1
--- /dev/null Wed Jan 26 23:25:36 2005
+++ gnupg/agent/command-ssh.c Wed Jan 26 23:25:36 2005
@@ -0,0 +1,2327 @@
+/* command-ssh.c - gpg-agent's ssh-agent emulation layer
+ * Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA
+ */
+
+#include <config.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <stdio.h>
+
+#include "agent.h"
+
+#include <gcrypt.h>
+
+#include "estream.h"
+
+
+
+/* Request types. */
+#define SSH_REQUEST_REQUEST_IDENTITIES 11
+#define SSH_REQUEST_SIGN_REQUEST 13
+#define SSH_REQUEST_ADD_IDENTITY 17
+#define SSH_REQUEST_REMOVE_IDENTITY 18
+#define SSH_REQUEST_REMOVE_ALL_IDENTITIES 19
+#define SSH_REQUEST_LOCK 22
+#define SSH_REQUEST_UNLOCK 23
+#define SSH_REQUEST_ADD_ID_CONSTRAINED 25
+
+/* Options. */
+#define SSH_OPT_CONSTRAIN_LIFETIME 1
+#define SSH_OPT_CONSTRAIN_CONFIRM 2
+
+/* Response types. */
+#define SSH_RESPONSE_SUCCESS 6
+#define SSH_RESPONSE_FAILURE 5
+#define SSH_RESPONSE_IDENTITIES_ANSWER 12
+#define SSH_RESPONSE_SIGN_RESPONSE 14
+
+
+
+
+/* Basic types. */
+
+/* A "byte". */
+typedef unsigned char byte_t;
+
+typedef int (*ssh_request_handler_t) (ctrl_t ctrl,
+ estream_t request, estream_t response);
+
+typedef struct ssh_request_spec
+{
+ byte_t type;
+ ssh_request_handler_t handler;
+} ssh_request_spec_t;
+
+typedef gpg_error_t (*ssh_key_modifier_t) (const char *elems, gcry_mpi_t *mpis);
+typedef gpg_error_t (*ssh_signature_encoder_t) (estream_t signature_blob,
+ gcry_mpi_t *mpis);
+
+typedef struct ssh_key_type_spec
+{
+ const char *ssh_identifier;
+ const char *identifier;
+ const char *elems_key_secret;
+ const char *elems_key_public;
+ const char *elems_secret;
+ const char *elems_signature;
+ const char *elems_sexp_order;
+ ssh_key_modifier_t key_modifier;
+ ssh_signature_encoder_t signature_encoder;
+ unsigned int flags;
+} ssh_key_type_spec_t;
+
+
+
+static uint32_t lifetime_default;
+
+/* General utility functions. */
+
+static void *
+realloc_secure (void *a, size_t n)
+{
+ void *p;
+
+ if (a)
+ p = gcry_realloc (a, n);
+ else
+ p = gcry_malloc_secure (n);
+
+ return p;
+}
+
+/* Primitive I/O functions. */
+
+static gpg_error_t
+es_read_byte (estream_t stream, byte_t *b)
+{
+ gpg_error_t err;
+ int ret;
+
+ ret = es_fgetc (stream);
+ if (ret == EOF)
+ {
+ if (es_ferror (stream))
+ err = gpg_error_from_errno (errno);
+ else
+ err = gpg_error (GPG_ERR_EOF);
+ }
+ else
+ {
+ *b = ret & 0xFF;
+ err = 0;
+ }
+
+ return err;
+}
+
+static gpg_error_t
+es_write_byte (estream_t stream, byte_t b)
+{
+ gpg_error_t err;
+ int ret;
+
+ ret = es_fputc (b, stream);
+ if (ret == EOF)
+ err = gpg_error_from_errno (errno);
+ else
+ err = 0;
+
+ return err;
+}
+
+static gpg_error_t
+es_read_uint32 (estream_t stream, uint32_t *uint32)
+{
+ unsigned char buffer[4];
+ size_t bytes_read;
+ gpg_error_t err;
+ int ret;
+
+ ret = es_read (stream, buffer, sizeof (buffer), &bytes_read);
+ if (ret)
+ err = gpg_error_from_errno (errno);
+ else
+ {
+ if (bytes_read != sizeof (buffer))
+ err = gpg_error (GPG_ERR_EOF);
+ else
+ {
+ uint32_t n;
+
+ n = (0
+ | ((uint32_t) (buffer[0] << 24))
+ | ((uint32_t) (buffer[1] << 16))
+ | ((uint32_t) (buffer[2] << 8))
+ | ((uint32_t) (buffer[3] << 0)));
+ *uint32 = n;
+ err = 0;
+ }
+ }
+
+ return err;
+}
+
+static gpg_error_t
+es_write_uint32 (estream_t stream, uint32_t uint32)
+{
+ unsigned char buffer[4];
+ gpg_error_t err;
+ int ret;
+
+ buffer[0] = (uint32 >> 24) & 0xFF;
+ buffer[1] = (uint32 >> 16) & 0xFF;
+ buffer[2] = (uint32 >> 8) & 0xFF;
+ buffer[3] = (uint32 >> 0) & 0xFF;
+
+ ret = es_write (stream, buffer, sizeof (buffer), NULL);
+ if (ret)
+ err = gpg_error_from_errno (errno);
+ else
+ err = 0;
+
+ return err;
+}
+
+static gpg_error_t
+es_read_data (estream_t stream, unsigned char *buffer, size_t size)
+{
+ gpg_error_t err;
+ size_t bytes_read;
+ int ret;
+
+ ret = es_read (stream, buffer, size, &bytes_read);
+ if (ret)
+ err = gpg_error_from_errno (errno);
+ else
+ {
+ if (bytes_read != size)
+ err = gpg_error (GPG_ERR_EOF);
+ else
+ err = 0;
+ }
+
+ return err;
+}
+
+static gpg_error_t
+es_write_data (estream_t stream, const unsigned char *buffer, size_t size)
+{
+ gpg_error_t err;
+ int ret;
+
+ ret = es_write (stream, buffer, size, NULL);
+ if (ret)
+ err = gpg_error_from_errno (errno);
+ else
+ err = 0;
+
+ return err;
+}
+
+static gpg_error_t
+es_read_string (estream_t stream, unsigned int secure,
+ unsigned char **string, uint32_t *string_size)
+{
+ gpg_error_t err;
+ unsigned char *buffer;
+ uint32_t length;
+
+ buffer = NULL;
+
+ /* Read string length. */
+ err = es_read_uint32 (stream, &length);
+ if (err)
+ goto out;
+
+ /* Allocate space. */
+ if (secure)
+ buffer = xtrymalloc_secure (length + 1);
+ else
+ buffer = xtrymalloc (length + 1);
+ if (! buffer)
+ {
+ /* FIXME: xtrymalloc_secure does not set errno, does it? */
+ err = gpg_error_from_errno (errno);
+ abort ();
+ goto out;
+ }
+
+ /* Read data. */
+ err = es_read_data (stream, buffer, length);
+ if (err)
+ goto out;
+
+ /* Finalize string object. */
+ buffer[length] = 0;
+ *string = buffer;
+ if (string_size)
+ *string_size = length;
+
+ out:
+
+ if (err)
+ xfree (buffer);
+
+ return err;
+}
+
+static gpg_error_t
+es_read_cstring (estream_t stream, char **string)
+{
+ unsigned char *buffer;
+ gpg_error_t err;
+
+ err = es_read_string (stream, 0, &buffer, NULL);
+ if (err)
+ goto out;
+
+ *string = (char *) buffer;
+
+ out:
+
+ return err;
+}
+
+static gpg_error_t
+es_write_string (estream_t stream,
+ const unsigned char *string, uint32_t string_n)
+{
+ gpg_error_t err;
+
+ err = es_write_uint32 (stream, string_n);
+ if (err)
+ goto out;
+
+ err = es_write_data (stream, string, string_n);
+
+ out:
+
+ return err;
+}
+
+static gpg_error_t
+es_write_cstring (estream_t stream, const char *string)
+{
+ gpg_error_t err;
+
+ err = es_write_string (stream,
+ (const unsigned char *) string, strlen (string));
+
+ return err;
+}
+
+static gpg_error_t
+es_read_mpi (estream_t stream, unsigned int secure, gcry_mpi_t *mpint)
+{
+ unsigned char *mpi_data;
+ uint32_t mpi_data_size;
+ gpg_error_t err;
+ gcry_mpi_t mpi;
+
+ mpi_data = NULL;
+
+ err = es_read_string (stream, secure, &mpi_data, &mpi_data_size);
+ if (err)
+ goto out;
+
+ err = gcry_mpi_scan (&mpi, GCRYMPI_FMT_STD, mpi_data, mpi_data_size, NULL);
+ if (err)
+ goto out;
+
+ *mpint = mpi;
+
+ out:
+
+ xfree (mpi_data);
+
+ return err;
+}
+
+static gpg_error_t
+es_write_mpi (estream_t stream, gcry_mpi_t mpint)
+{
+ unsigned char *mpi_buffer;
+ size_t mpi_buffer_n;
+ gpg_error_t err;
+
+ mpi_buffer = NULL;
+
+ err = gcry_mpi_aprint (GCRYMPI_FMT_STD, &mpi_buffer, &mpi_buffer_n, mpint);
+ if (err)
+ goto out;
+
+ err = es_write_string (stream, mpi_buffer, mpi_buffer_n);
+
+ out:
+
+ xfree (mpi_buffer);
+
+ return err;
+}
+
+static gpg_error_t
+es_read_file (const char *filename, unsigned char **buffer, size_t *buffer_n)
+{
+ unsigned char *buffer_new;
+ struct stat statbuf;
+ estream_t stream;
+ gpg_error_t err;
+ int ret;
+
+ buffer_new = NULL;
+ err = 0;
+
+ stream = es_fopen (filename, "r");
+ if (! stream)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ ret = fstat (es_fileno (stream), &statbuf);
+ if (ret)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ buffer_new = xtrymalloc (statbuf.st_size);
+ if (! buffer_new)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ err = es_read_data (stream, buffer_new, statbuf.st_size);
+ if (err)
+ goto out;
+
+ *buffer = buffer_new;
+ *buffer_n = statbuf.st_size;
+
+ out:
+
+ if (stream)
+ es_fclose (stream);
+
+ if (err)
+ xfree (buffer_new);
+
+ return err;
+}
+
+static gpg_error_t
+es_copy (estream_t dst, estream_t src)
+{
+ char buffer[BUFSIZ];
+ size_t bytes_read;
+ gpg_error_t err;
+ int ret;
+
+ err = 0;
+ while (1)
+ {
+ ret = es_read (src, buffer, sizeof (buffer), &bytes_read);
+ if (ret || (! bytes_read))
+ {
+ if (ret)
+ err = gpg_error_from_errno (errno);
+ break;
+ }
+ ret = es_write (dst, buffer, bytes_read, NULL);
+ if (ret)
+ {
+ err = gpg_error_from_errno (errno);
+ break;
+ }
+ }
+
+ return err;
+}
+
+
+
+/* MPI lists. */
+
+static void
+mpint_list_free (gcry_mpi_t *mpi_list)
+{
+ if (mpi_list)
+ {
+ unsigned int i;
+
+ for (i = 0; mpi_list[i]; i++)
+ gcry_mpi_release (mpi_list[i]);
+ xfree (mpi_list);
+ }
+}
+
+static gpg_error_t
+ssh_receive_mpint_list (estream_t stream, int secret,
+ ssh_key_type_spec_t key_spec, gcry_mpi_t **mpi_list)
+{
+ const char *elems_secret;
+ const char *elems;
+ unsigned int elems_n;
+ gcry_mpi_t *mpis;
+ unsigned int i;
+ gpg_error_t err;
+ int elem_is_secret;
+
+ mpis = NULL;
+ err = 0;
+
+ if (secret)
+ {
+ elems = key_spec.elems_key_secret;
+ elems_secret = key_spec.elems_secret;
+ }
+ else
+ {
+ elems = key_spec.elems_key_public;
+ elems_secret = "";
+ }
+ elems_n = strlen (elems);
+
+ mpis = xtrymalloc (sizeof (*mpis) * (elems_n + 1));
+ if (! mpis)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ memset (mpis, 0, sizeof (*mpis) * (elems_n + 1));
+
+ for (i = 0; i < elems_n; i++)
+ {
+ elem_is_secret = strchr (elems_secret, elems[i]) ? 1 : 0;
+ err = es_read_mpi (stream, elem_is_secret, &mpis[i]);
+ if (err)
+ break;
+ }
+ if (err)
+ goto out;
+
+ *mpi_list = mpis;
+
+ out:
+
+ if (err)
+ mpint_list_free (mpis);
+
+ return err;
+}
+
+
+
+static gpg_error_t
+ssh_key_modifier_rsa (const char *elems, gcry_mpi_t *mpis)
+{
+ gcry_mpi_t p;
+ gcry_mpi_t q;
+ gcry_mpi_t u;
+
+ if (strcmp (elems, "nedupq"))
+ /* Modifying only necessary for secret keys. */
+ goto out;
+
+ u = mpis[3];
+ p = mpis[4];
+ q = mpis[5];
+
+ if (gcry_mpi_cmp (p, q) > 0)
+ {
+ /* P shall be smaller then Q! Swap primes. iqmp becomes u. */
+ gcry_mpi_t tmp;
+
+ tmp = mpis[4];
+ mpis[4] = mpis[5];
+ mpis[5] = tmp;
+ }
+ else
+ /* U needs to be recomputed. */
+ gcry_mpi_invm (u, p, q);
+
+ out:
+
+ return 0;
+}
+
+static gpg_error_t
+ssh_signature_encoder_rsa (estream_t signature_blob, gcry_mpi_t *mpis)
+{
+ unsigned char *data;
+ size_t data_n;
+ gpg_error_t err;
+ gcry_mpi_t s;
+
+ s = mpis[0];
+
+ err = gcry_mpi_aprint (GCRYMPI_FMT_USG, &data, &data_n, s);
+ if (err)
+ goto out;
+
+ err = es_write_string (signature_blob, data, data_n);
+ xfree (data);
+
+ out:
+
+ return err;
+}
+
+#define SSH_DSA_SIGNATURE_PADDING 20
+#define SSH_DSA_SIGNATURE_ELEMS 2
+
+static gpg_error_t
+ssh_signature_encoder_dsa (estream_t signature_blob, gcry_mpi_t *mpis)
+{
+ unsigned char buffer[SSH_DSA_SIGNATURE_PADDING * SSH_DSA_SIGNATURE_ELEMS];
+ unsigned char *data;
+ size_t data_n;
+ gpg_error_t err;
+ int i;
+
+ data = NULL;
+
+ for (i = 0; i < 2; i++)
+ {
+ err = gcry_mpi_aprint (GCRYMPI_FMT_USG, &data, &data_n, mpis[i]);
+ if (err)
+ break;
+
+ if (data_n > SSH_DSA_SIGNATURE_PADDING)
+ {
+ err = gpg_error (GPG_ERR_INTERNAL); /* FIXME? */
+ break;
+ }
+
+ memset (buffer + (i * SSH_DSA_SIGNATURE_PADDING), 0,
+ SSH_DSA_SIGNATURE_PADDING - data_n);
+ memcpy (buffer + (i * SSH_DSA_SIGNATURE_PADDING)
+ + (SSH_DSA_SIGNATURE_PADDING - data_n), data, data_n);
+
+ xfree (data);
+ data = NULL;
+ }
+ if (err)
+ goto out;
+
+ err = es_write_string (signature_blob, buffer, sizeof (buffer));
+
+ out:
+
+ xfree (data);
+
+ return err;
+}
+
+#define SPEC_FLAG_USE_PKCS1V2 (1 << 0)
+
+
+/* Table holding key type specifications. */
+static ssh_key_type_spec_t ssh_key_types[] =
+ {
+ {
+ "ssh-rsa", "rsa", "nedupq", "en", "dupq", "s", "nedpqu",
+ ssh_key_modifier_rsa, ssh_signature_encoder_rsa,
+ SPEC_FLAG_USE_PKCS1V2
+ },
+ {
+ "ssh-dss", "dsa", "pqgyx", "pqgy", "x", "rs", "pqgyx",
+ NULL, ssh_signature_encoder_dsa,
+ 0
+ },
+ };
+
+
+
+/* S-Expressions. */
+
+static gpg_error_t
+ssh_sexp_construct (gcry_sexp_t *sexp,
+ ssh_key_type_spec_t key_spec, int secret,
+ gcry_mpi_t *mpis, const char *comment)
+{
+ gcry_sexp_t sexp_new;
+ char *sexp_template;
+ size_t sexp_template_n;
+ gpg_error_t err;
+ const char *elems;
+ size_t elems_n;
+ unsigned int i;
+ unsigned int j;
+ void **arg_list;
+
+ err = 0;
+ sexp_new = NULL;
+ arg_list = NULL;
+ if (secret)
+ elems = key_spec.elems_sexp_order;
+ else
+ elems = key_spec.elems_key_public;
+ elems_n = strlen (elems);
+
+ sexp_template_n = 33 + strlen (key_spec.identifier) + (elems_n * 6) - (! secret);
+ sexp_template = xtrymalloc (sexp_template_n);
+ if (! sexp_template)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ arg_list = xtrymalloc (sizeof (*arg_list) * (elems_n + 1));
+ if (! arg_list)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ sprintf (sexp_template, "(%s-key (%s ",
+ secret ? "private" : "public", key_spec.identifier);
+ for (i = 0; i < elems_n; i++)
+ {
+ sprintf (strchr (sexp_template, 0), "(%c %%m)", elems[i]);
+ if (secret)
+ {
+ for (j = 0; j < elems_n; j++)
+ if (key_spec.elems_key_secret[j] == elems[i])
+ break;
+ }
+ else
+ j = i;
+ arg_list[i] = &mpis[j];
+ }
+ arg_list[i] = &comment;
+ sprintf (strchr (sexp_template, 0), ") (comment %%s))");
+
+ err = gcry_sexp_build_array (&sexp_new, NULL, sexp_template, arg_list);
+ if (err)
+ goto out;
+
+ *sexp = sexp_new;
+
+ out:
+
+ xfree (arg_list);
+ xfree (sexp_template);
+
+ return err;
+}
+
+static gpg_error_t
+ssh_sexp_extract (gcry_sexp_t sexp,
+ ssh_key_type_spec_t key_spec, int *secret,
+ gcry_mpi_t **mpis, const char **comment)
+{
+ gpg_error_t err;
+ gcry_sexp_t value_list;
+ gcry_sexp_t value_pair;
+ gcry_sexp_t comment_list;
+ unsigned int i;
+ char *comment_new;
+ const char *data;
+ size_t data_n;
+ int is_secret;
+ size_t elems_n;
+ const char *elems;
+ gcry_mpi_t *mpis_new;
+ gcry_mpi_t mpi;
+
+ err = 0;
+ value_list = NULL;
+ value_pair = NULL;
+ comment_list = NULL;
+ comment_new = NULL;
+ mpis_new = NULL;
+
+ data = gcry_sexp_nth_data (sexp, 0, &data_n);
+ if (! data)
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ goto out;
+ }
+
+ if ((data_n == 10) && (! strncmp (data, "public-key", 10)))
+ {
+ is_secret = 0;
+ elems = key_spec.elems_key_public;
+ }
+ else if (((data_n == 11) && (! strncmp (data, "private-key", 11)))
+ || ((data_n == 21) && (! strncmp (data, "protected-private-key", 21))))
+ {
+ is_secret = 1;
+ elems = key_spec.elems_key_secret;
+ }
+ else
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ goto out;
+ }
+
+ elems_n = strlen (elems);
+ mpis_new = xtrymalloc (sizeof (*mpis_new) * (elems_n + 1));
+ if (! mpis_new)
+ {
+ err = gpg_error_from_errno (errno); /* FIXME, xtrymalloc+errno. */
+ goto out;
+ }
+ memset (mpis_new, 0, sizeof (*mpis_new) * (elems_n + 1));
+
+ value_list = gcry_sexp_find_token (sexp, key_spec.identifier, 0);
+ if (! value_list)
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ goto out;
+ }
+
+ for (i = 0; i < elems_n; i++)
+ {
+ value_pair = gcry_sexp_find_token (value_list, elems + i, 1);
+ if (! value_pair)
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ break;
+ }
+
+ mpi = gcry_sexp_nth_mpi (value_pair, 1, GCRYMPI_FMT_USG);
+ if (! mpi)
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ break;
+ }
+ mpis_new[i] = mpi;
+ gcry_sexp_release (value_pair);
+ value_pair = NULL;
+ }
+ if (err)
+ goto out;
+
+ /* We do not require a comment sublist to be present here. */
+ data = NULL;
+ data_n = 0;
+
+ comment_list = gcry_sexp_find_token (sexp, "comment", 0);
+ if (comment_list)
+ data = gcry_sexp_nth_data (comment_list, 1, &data_n);
+ if (! data)
+ {
+ data = "(none)";
+ data_n = 6;
+ }
+
+ comment_new = xtrymalloc (data_n + 1);
+ if (! comment_new)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+ strncpy (comment_new, data, data_n);
+ comment_new[data_n] = 0;
+
+ if (secret)
+ *secret = is_secret;
+ *mpis = mpis_new;
+ *comment = comment_new;
+
+ out:
+
+ gcry_sexp_release (value_list);
+ gcry_sexp_release (value_pair);
+ gcry_sexp_release (comment_list);
+
+ if (err)
+ {
+ xfree (comment_new);
+ mpint_list_free (mpis_new);
+ }
+
+ return err;
+}
+
+static gpg_error_t
+ssh_sexp_extract_key_type (gcry_sexp_t sexp, const char **key_type)
+{
+ gcry_sexp_t sublist;
+ char *key_type_new;
+ const char *data;
+ size_t data_n;
+ gpg_error_t err;
+
+ err = 0;
+ key_type_new = NULL;
+
+ sublist = gcry_sexp_nth (sexp, 1);
+ if (! sublist)
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ goto out;
+ }
+
+ data = gcry_sexp_nth_data (sublist, 0, &data_n);
+ if (! data)
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ goto out;
+ }
+
+ key_type_new = xtrymalloc (data_n + 1);
+ if (! key_type_new)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ strncpy (key_type_new, data, data_n);
+ key_type_new[data_n] = 0;
+ *key_type = key_type_new;
+
+ out:
+
+ gcry_sexp_release (sublist);
+
+ return err;
+}
+
+
+
+/* Key I/O. */
+
+static gpg_error_t
+ssh_key_type_lookup (const char *ssh_name, const char *name,
+ ssh_key_type_spec_t *spec)
+{
+ gpg_error_t err;
+ unsigned int i;
+
+ for (i = 0; i < DIM (ssh_key_types); i++)
+ if ((ssh_name && (! strcmp (ssh_name, ssh_key_types[i].ssh_identifier)))
+ || (name && (! strcmp (name, ssh_key_types[i].identifier))))
+ break;
+
+ if (i == DIM (ssh_key_types))
+ err = gpg_error (GPG_ERR_NOT_FOUND);
+ else
+ {
+ *spec = ssh_key_types[i];
+ err = 0;
+ }
+
+ return err;
+}
+
+static gpg_error_t
+ssh_receive_key (estream_t stream, gcry_sexp_t *key_new, int secret, int read_comment,
+ ssh_key_type_spec_t *key_spec)
+{
+ gpg_error_t err;
+ char *key_type;
+ char *comment;
+ gcry_sexp_t key;
+ ssh_key_type_spec_t spec;
+ gcry_mpi_t *mpi_list;
+ const char *elems;
+
+ mpi_list = NULL;
+ key_type = NULL;
+ comment = "";
+ key = NULL;
+
+ err = es_read_cstring (stream, &key_type);
+ if (err)
+ goto out;
+
+ err = ssh_key_type_lookup (key_type, NULL, &spec);
+ if (err)
+ goto out;
+
+ err = ssh_receive_mpint_list (stream, secret, spec, &mpi_list);
+ if (err)
+ goto out;
+
+ if (read_comment)
+ {
+ err = es_read_cstring (stream, &comment);
+ if (err)
+ goto out;
+ }
+
+ if (secret)
+ elems = spec.elems_key_secret;
+ else
+ elems = spec.elems_key_public;
+
+ if (spec.key_modifier)
+ {
+ err = (*spec.key_modifier) (elems, mpi_list);
+ if (err)
+ goto out;
+ }
+
+ err = ssh_sexp_construct (&key, spec, secret, mpi_list, comment);
+ if (err)
+ goto out;
+
+ if (key_spec)
+ *key_spec = spec;
+ *key_new = key;
+
+ out:
+
+ mpint_list_free (mpi_list);
+ xfree (key_type);
+ if (read_comment)
+ xfree (comment);
+
+ return err;
+}
+
+static gpg_error_t
+ssh_convert_key_to_blob (unsigned char **blob, size_t *blob_size,
+ const char *type, gcry_mpi_t *mpis)
+{
+ unsigned char *blob_new;
+ long int blob_size_new;
+ estream_t stream;
+ gpg_error_t err;
+ unsigned int i;
+
+ blob_new = NULL;
+ stream = NULL;
+ err = 0;
+
+ stream = es_mopen (NULL, 0, 0, 1, NULL, NULL, "r+");
+ if (! stream)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ err = es_write_cstring (stream, type);
+ if (err)
+ goto out;
+
+ for (i = 0; mpis[i] && (! err); i++)
+ err = es_write_mpi (stream, mpis[i]);
+ if (err)
+ goto out;
+
+ blob_size_new = es_ftell (stream);
+ if (blob_size_new == -1)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ err = es_fseek (stream, 0, SEEK_SET);
+ if (err)
+ goto out;
+
+ blob_new = xtrymalloc (blob_size_new);
+ if (! blob_new)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ err = es_read_data (stream, blob_new, blob_size_new);
+ if (err)
+ goto out;
+
+ *blob = blob_new;
+ *blob_size = blob_size_new;
+
+ out:
+
+ if (stream)
+ es_fclose (stream);
+ if (err)
+ xfree (blob_new);
+
+ return err;
+}
+
+
+static gpg_error_t
+ssh_send_key_public (estream_t stream, gcry_sexp_t key_public)
+{
+ ssh_key_type_spec_t spec;
+ gcry_mpi_t *mpi_list;
+ const char *key_type;
+ const char *comment;
+ unsigned char *blob;
+ size_t blob_n;
+ gpg_error_t err;
+
+ key_type = NULL;
+ mpi_list = NULL;
+ comment = NULL;
+ blob = NULL;
+
+ err = ssh_sexp_extract_key_type (key_public, &key_type);
+ if (err)
+ goto out;
+
+ err = ssh_key_type_lookup (NULL, key_type, &spec);
+ if (err)
+ goto out;
+
+ err = ssh_sexp_extract (key_public, spec, NULL, &mpi_list, &comment);
+ if (err)
+ goto out;
+
+ err = ssh_convert_key_to_blob (&blob, &blob_n, spec.ssh_identifier, mpi_list);
+ if (err)
+ goto out;
+
+ err = es_write_string (stream, blob, blob_n);
+ if (err)
+ goto out;
+
+ err = es_write_cstring (stream, comment);
+
+ out:
+
+ mpint_list_free (mpi_list);
+ xfree ((void *) key_type);
+ xfree ((void *) comment);
+ xfree (blob);
+
+ return err;
+}
+
+static gpg_error_t
+ssh_read_key_public_from_blob (unsigned char *blob, size_t blob_size,
+ gcry_sexp_t *key_public,
+ ssh_key_type_spec_t *key_spec)
+{
+ estream_t blob_stream;
+ gpg_error_t err;
+
+ err = 0;
+
+ blob_stream = es_mopen (NULL, 0, 0, 1, NULL, NULL, "r+");
+ if (! blob_stream)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ err = es_write_data (blob_stream, blob, blob_size);
+ if (err)
+ goto out;
+
+ err = es_fseek (blob_stream, 0, SEEK_SET);
+ if (err)
+ goto out;
+
+ err = ssh_receive_key (blob_stream, key_public, 0, 0, key_spec);
+
+ out:
+
+ if (blob_stream)
+ es_fclose (blob_stream);
+
+ return err;
+}
+
+
+
+static gpg_error_t
+key_secret_to_public (gcry_sexp_t *key_public,
+ ssh_key_type_spec_t spec, gcry_sexp_t key_secret)
+{
+ gpg_error_t err;
+ gcry_sexp_t value_pair;
+ unsigned int i;
+ gcry_mpi_t *mpis;
+ gcry_mpi_t mpi;
+ void **arglist;
+ size_t elems_n;
+ char *template;
+ size_t template_n;
+ const char *elems;
+ char *comment;
+ const char *data;
+ size_t data_n;
+
+ err = 0;
+ mpis = NULL;
+ arglist = NULL;
+ comment = NULL;
+ template = NULL;
+ value_pair = NULL;
+
+ elems = spec.elems_key_public;
+ elems_n = strlen (elems);
+
+ data = NULL;
+ value_pair = gcry_sexp_find_token (key_secret, "comment", 0);
+ if (value_pair)
+ data = gcry_sexp_nth_data (value_pair, 1, &data_n);
+ if (! data)
+ {
+ data = "";
+ data_n = 0;
+ }
+
+ comment = xtrymalloc (data_n + 1);
+ if (! comment)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+ strncpy (comment, data, data_n);
+ comment[data_n] = 0;
+
+ gcry_sexp_release (value_pair);
+ value_pair = NULL;
+
+ template_n = 29 + strlen (spec.identifier) + (elems_n * 7) + 1;
+ template = xtrymalloc (template_n);
+ if (! template)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ mpis = xtrymalloc (sizeof (*mpis) * (elems_n + 1));
+ if (! mpis)
+ {
+ err = gpg_error_from_errno (errno); /* FIXME: errno. */
+ goto out;
+ }
+ memset (mpis, 0, sizeof (*mpis) * (elems_n + 1));
+
+ arglist = xtrymalloc (sizeof (*arglist) * (elems_n + 1));
+ if (! arglist)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ for (i = 0; i < elems_n; i++)
+ {
+ value_pair = gcry_sexp_find_token (key_secret, elems + i, 1);
+ if (! value_pair)
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ break;
+ }
+ mpi = gcry_sexp_nth_mpi (value_pair, 1, GCRYMPI_FMT_USG);
+ if (! mpi)
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ break;
+ }
+ gcry_sexp_release (value_pair);
+ value_pair = NULL;
+
+ mpis[i] = mpi;
+ arglist[i] = &mpis[i];
+ mpi = NULL;
+ }
+ if (err)
+ goto out;
+
+ sprintf (template, "(public-key (%s", spec.identifier);
+ for (i = 0; i < elems_n; i++)
+ sprintf (strchr (template, 0)," (%c %%m)", elems[i]);
+ sprintf (strchr (template, 0), ") (comment %%s))");
+ arglist[i] = &comment;
+
+ err = gcry_sexp_build_array (key_public, NULL, template, arglist);
+
+ out:
+
+ gcry_sexp_release (value_pair);
+ xfree (template);
+ mpint_list_free (mpis);
+ xfree (arglist);
+ xfree (comment);
+
+ return err;
+}
+
+
+
+static char *
+make_cstring (const char *data, size_t data_n)
+{
+ char *s;
+
+ s = xtrymalloc (data_n + 1);
+ if (s)
+ {
+ strncpy (s, data, data_n);
+ s[data_n] = 0;
+ }
+
+ return s;
+}
+
+
+
+/* Request handler. */
+
+static int
+ssh_handler_request_identities (ctrl_t ctrl, estream_t request, estream_t response)
+{
+ const char *key_type;
+ ssh_key_type_spec_t spec;
+ struct dirent *dir_entry;
+ char *key_directory;
+ size_t key_directory_n;
+ char *key_path;
+ unsigned char *buffer;
+ size_t buffer_n;
+ uint32_t key_counter;
+ estream_t key_blobs;
+ gcry_sexp_t key_secret;
+ gcry_sexp_t key_public;
+ DIR *dir;
+ gpg_error_t err;
+ int ret;
+ int bad;
+
+ if (DBG_COMMAND)
+ log_debug ("[ssh-agent] request identities\n");
+
+ /* Prepare buffer stream. */
+
+ key_directory = NULL;
+ key_secret = NULL;
+ key_public = NULL;
+ key_type = NULL;
+ key_path = NULL;
+ key_counter = 0;
+ buffer = NULL;
+ dir = NULL;
+ bad = 0;
+ err = 0;
+
+ key_blobs = es_mopen (NULL, 0, 0, 1, NULL, NULL, "r+");
+ if (! key_blobs)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ /* Open key directory. */
+ key_directory = make_filename (opt.homedir, GNUPG_PRIVATE_KEYS_DIR, NULL);
+ if (! key_directory)
+ {
+ err = gpg_err_code_from_errno (errno);
+ goto out;
+ }
+ key_directory_n = strlen (key_directory);
+
+ key_path = xtrymalloc (key_directory_n + 46);
+ if (! key_path)
+ {
+ err = gpg_err_code_from_errno (errno);
+ goto out;
+ }
+
+ sprintf (key_path, "%s/", key_directory);
+ sprintf (key_path + key_directory_n + 41, ".key");
+
+ dir = opendir (key_directory);
+ if (! dir)
+ {
+ err = gpg_err_code_from_errno (errno);
+ goto out;
+ }
+
+ /* Iterate over key files. */
+
+ /* FIXME: make sure that buffer gets deallocated properly. */
+
+ while (1)
+ {
+ dir_entry = readdir (dir);
+ if (dir_entry)
+ {
+ if ((strlen (dir_entry->d_name) == 44)
+ && (! strncmp (dir_entry->d_name + 40, ".key", 4)))
+ {
+ strncpy (key_path + key_directory_n + 1, dir_entry->d_name, 40);
+
+ /* Read file content. */
+ err = es_read_file (key_path, &buffer, &buffer_n);
+ if (err)
+ break;
+
+ err = gcry_sexp_sscan (&key_secret, NULL, buffer, buffer_n);
+ if (err)
+ break;
+
+ xfree (buffer);
+ buffer = NULL;
+
+ err = ssh_sexp_extract_key_type (key_secret, &key_type);
+ if (err)
+ break;
+
+ err = ssh_key_type_lookup (NULL, key_type, &spec);
+ if (err)
+ break;
+
+ xfree ((void *) key_type);
+ key_type = NULL;
+
+ err = key_secret_to_public (&key_public, spec, key_secret);
+ if (err)
+ break;
+
+ gcry_sexp_release (key_secret);
+ key_secret = NULL;
+
+ err = ssh_send_key_public (key_blobs, key_public);
+ if (err)
+ break;
+
+ gcry_sexp_release (key_public);
+ key_public = NULL;
+
+ key_counter++;
+ }
+ }
+ else
+ break;
+ }
+ if (err)
+ goto out;
+
+ ret = es_fseek (key_blobs, 0, SEEK_SET);
+ if (ret)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ out:
+
+ /* Send response. */
+
+ gcry_sexp_release (key_secret);
+ gcry_sexp_release (key_public);
+
+ es_write_byte (response, SSH_RESPONSE_IDENTITIES_ANSWER);
+ if (! es_ferror (response))
+ es_write_uint32 (response, err ? 0 : key_counter);
+ if (! (err || es_ferror (response)))
+ es_copy (response, key_blobs);
+
+ if (key_blobs)
+ es_fclose (key_blobs);
+ if (dir)
+ closedir (dir);
+
+ free (key_directory);
+ xfree (key_path);
+ xfree (buffer);
+ xfree ((void *) key_type); /* FIXME? */
+
+ return bad;
+}
+
+static gpg_error_t
+data_hash (unsigned char *data, size_t data_n,
+ int md_algorithm, unsigned char *hash)
+{
+ gcry_md_hash_buffer (md_algorithm, hash, data, data_n);
+
+ return 0;
+}
+
+static gpg_error_t
+data_sign (CTRL ctrl, ssh_signature_encoder_t sig_encoder,
+ unsigned char **sig, size_t *sig_n)
+{
+ char description[] = "Please provide the passphrase for key `%c':";
+ gpg_error_t err;
+ gcry_sexp_t signature_sexp;
+ estream_t stream;
+ gcry_sexp_t valuelist;
+ gcry_sexp_t sublist;
+ gcry_mpi_t sig_value;
+ unsigned char *sig_blob;
+ size_t sig_blob_n;
+ const char *identifier;
+ const char *identifier_raw;
+ size_t identifier_n;
+ ssh_key_type_spec_t spec;
+ int ret;
+ unsigned int i;
+ const char *elems;
+ size_t elems_n;
+ gcry_mpi_t *mpis;
+
+ signature_sexp = NULL;
+ identifier = NULL;
+ valuelist = NULL;
+ sublist = NULL;
+ sig_blob = NULL;
+ sig_blob_n = 0;
+ stream = NULL;
+ sig_value = NULL;
+ mpis = NULL;
+
+ err = agent_pksign_do (ctrl, description, &signature_sexp, 0);
+ if (err)
+ goto out;
+
+ valuelist = gcry_sexp_nth (signature_sexp, 1);
+ if (! valuelist)
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ goto out;
+ }
+
+ stream = es_mopen (NULL, 0, 0, 1, NULL, NULL, "r+");
+ if (! stream)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ identifier_raw = gcry_sexp_nth_data (valuelist, 0, &identifier_n);
+ if (! identifier_raw)
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ goto out;
+ }
+
+ identifier = make_cstring (identifier_raw, identifier_n);
+ if (! identifier)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ err = ssh_key_type_lookup (NULL, identifier, &spec);
+ if (err)
+ goto out;
+
+ err = es_write_cstring (stream, spec.ssh_identifier);
+ if (err)
+ goto out;
+
+ elems = spec.elems_signature;
+ elems_n = strlen (elems);
+
+ mpis = xtrymalloc (sizeof (*mpis) * (elems_n + 1));
+ if (! mpis)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+ memset (mpis, 0, sizeof (*mpis) * (elems_n + 1));
+
+ for (i = 0; i < elems_n; i++)
+ {
+ sublist = gcry_sexp_find_token (valuelist, spec.elems_signature + i, 1);
+ if (! sublist)
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ break;
+ }
+
+ sig_value = gcry_sexp_nth_mpi (sublist, 1, GCRYMPI_FMT_USG);
+ if (! sig_value)
+ {
+ err = gpg_error (GPG_ERR_INTERNAL); /* FIXME? */
+ break;
+ }
+ gcry_sexp_release (sublist);
+ sublist = NULL;
+
+ mpis[i] = sig_value;
+ }
+ if (err)
+ goto out;
+
+ err = (*sig_encoder) (stream, mpis);
+ if (err)
+ goto out;
+
+ sig_blob_n = es_ftell (stream);
+ if (sig_blob_n == -1)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ sig_blob = xtrymalloc (sig_blob_n);
+ if (! sig_blob)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ ret = es_fseek (stream, 0, SEEK_SET);
+ if (ret)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ err = es_read_data (stream, sig_blob, sig_blob_n);
+ if (err)
+ goto out;
+
+ *sig = (char *) sig_blob;
+ *sig_n = sig_blob_n;
+
+ out:
+
+ if (err)
+ xfree (sig_blob);
+
+ if (stream)
+ es_fclose (stream);
+ gcry_sexp_release (valuelist);
+ gcry_sexp_release (signature_sexp);
+ gcry_sexp_release (sublist);
+ mpint_list_free (mpis);
+ xfree ((void *) identifier);
+
+ return err;
+}
+
+static int
+ssh_handler_sign_request (ctrl_t ctrl, estream_t request, estream_t response)
+{
+ gcry_sexp_t key;
+ ssh_key_type_spec_t spec;
+ unsigned char hash[MAX_DIGEST_LEN];
+ unsigned int hash_n;
+ unsigned char key_grip[20];
+ unsigned char *key_blob;
+ uint32_t key_blob_size;
+ unsigned char *data;
+ unsigned char *sig;
+ size_t sig_n;
+ uint32_t data_size;
+ uint32_t flags;
+ const void *p;
+ gpg_error_t err;
+ int bad;
+
+ key_blob = NULL;
+ data = NULL;
+ sig = NULL;
+ key = NULL;
+ bad = 0;
+
+ if (DBG_COMMAND)
+ log_debug ("[ssh-agent] sign request\n");
+
+ /* Receive key. */
+
+ err = es_read_string (request, 0, &key_blob, &key_blob_size);
+ if (err)
+ {
+ bad = 1;
+ goto out;
+ }
+
+ err = ssh_read_key_public_from_blob (key_blob, key_blob_size, &key, &spec);
+ if (err)
+ {
+ bad = 1;
+ goto out;
+ }
+
+ /* Receive data to sign. */
+ err = es_read_string (request, 0, &data, &data_size);
+ if (err)
+ {
+ bad = 1;
+ goto out;
+ }
+
+ /* FIXME? */
+ err = es_read_uint32 (request, &flags);
+ if (err)
+ {
+ bad = 1;
+ goto out;
+ }
+
+ /* Hash data. */
+ hash_n = gcry_md_get_algo_dlen (GCRY_MD_SHA1);
+ if (! hash_n)
+ {
+ err = gpg_error (GPG_ERR_INTERNAL);
+ goto out;
+ }
+ err = data_hash (data, data_size, GCRY_MD_SHA1, hash);
+ if (err)
+ goto out;
+
+ /* Calculate key grip. */
+ p = gcry_pk_get_keygrip (key, key_grip);
+ if (! p)
+ {
+ err = gpg_error (GPG_ERR_INTERNAL); /* FIXME? */
+ goto out;
+ }
+
+ /* Sign data. */
+
+ ctrl->digest.algo = GCRY_MD_SHA1;
+ memcpy (ctrl->digest.value, hash, hash_n);
+ ctrl->digest.valuelen = hash_n;
+ ctrl->digest.raw_value = ! (spec.flags & SPEC_FLAG_USE_PKCS1V2);
+ ctrl->have_keygrip = 1;
+ memcpy (ctrl->keygrip, key_grip, 20);
+
+ err = data_sign (ctrl, spec.signature_encoder, &sig, &sig_n);
+
+ out:
+
+ if (! bad)
+ {
+ /* Done. */
+ es_write_byte (response, SSH_RESPONSE_SIGN_RESPONSE);
+ if (! es_ferror (response))
+ {
+ if (! err)
+ es_write_string (response, sig, sig_n);
+ else
+ es_write_byte (response, SSH_RESPONSE_FAILURE);
+ }
+ }
+
+ gcry_sexp_release (key);
+ xfree (key_blob);
+ xfree (data);
+ xfree (sig);
+
+ return bad;
+}
+
+static gpg_error_t
+get_passphrase (const char *description, size_t passphrase_n, char *passphrase)
+{
+ struct pin_entry_info_s *pi;
+ gpg_error_t err;
+
+ err = 0;
+ pi = gcry_calloc_secure (1, sizeof (*pi) + passphrase_n + 1);
+ if (! pi)
+ {
+ err = gpg_error (GPG_ERR_ENOMEM);
+ goto out;
+ }
+
+ pi->min_digits = 0; /* We want a real passphrase. */
+ pi->max_digits = 8;
+ pi->max_tries = 1;
+ pi->failed_tries = 0;
+ pi->check_cb = NULL;
+ pi->check_cb_arg = NULL;
+ pi->cb_errtext = NULL;
+ pi->max_length = 100;
+
+ err = agent_askpin (NULL, description, NULL, pi);
+ if (err)
+ goto out;
+
+ memcpy (passphrase, pi->pin, passphrase_n);
+ passphrase[passphrase_n] = 0;
+
+ out:
+
+ xfree (pi);
+
+ return err;
+}
+
+static gpg_error_t
+ssh_key_extract_comment (gcry_sexp_t key, char **comment)
+{
+ gcry_sexp_t comment_list;
+ char *comment_new;
+ const char *data;
+ size_t data_n;
+ gpg_error_t err;
+
+ comment_list = gcry_sexp_find_token (key, "comment", 0);
+ if (! comment_list)
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ goto out;
+ }
+
+ data = gcry_sexp_nth_data (comment_list, 1, &data_n);
+ if (! data)
+ {
+ err = gpg_error (GPG_ERR_INV_SEXP);
+ goto out;
+ }
+
+ comment_new = xtrymalloc (data_n + 1);
+ if (! comment_new)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ strncpy (comment_new, data, data_n);
+ comment_new[data_n] = 0;
+ *comment = comment_new;
+ err = 0;
+
+ out:
+
+ gcry_sexp_release (comment_list);
+
+ return err;
+}
+
+static gpg_error_t
+ssh_key_grip (gcry_sexp_t key, char *buffer)
+{
+ gpg_error_t err;
+ char *p;
+
+ /* FIXME: unsigned vs. signed. */
+
+ p = gcry_pk_get_keygrip (key, buffer);
+ if (! p)
+ err = gpg_error (GPG_ERR_INTERNAL); /* FIXME? */
+ else
+ err = 0;
+
+ return err;
+}
+
+static gpg_error_t
+ssh_key_to_buffer (gcry_sexp_t key, const char *passphrase,
+ unsigned char **buffer, size_t *buffer_n)
+{
+ unsigned char *buffer_new;
+ unsigned int buffer_new_n;
+ gpg_error_t err;
+
+ err = 0;
+ buffer_new_n = gcry_sexp_sprint (key, GCRYSEXP_FMT_CANON, NULL, 0);
+ buffer_new = xtrymalloc (buffer_new_n);
+ /* FIXME: secmem? */
+ if (! buffer_new)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ gcry_sexp_sprint (key, GCRYSEXP_FMT_CANON, buffer_new, buffer_new_n);
+ /* FIXME: guarantee? */
+
+ err = agent_protect (buffer_new, passphrase, buffer, buffer_n);
+
+ out:
+
+ xfree (buffer_new);
+
+ return err;
+}
+
+static gpg_error_t
+ssh_identity_register (gcry_sexp_t key, int ttl)
+{
+ unsigned char key_grip_raw[21];
+ unsigned char *buffer;
+ unsigned int buffer_n;
+ char passphrase[100];
+ size_t description_length;
+ char *description;
+ char key_grip[41];
+ char *comment;
+ gpg_error_t err;
+
+ int ret;
+
+ if (DBG_COMMAND)
+ log_debug ("[ssh-agent] registering identity `%s'\n", key_grip);
+
+ description = NULL;
+ comment = NULL;
+ buffer = NULL;
+
+ err = ssh_key_grip (key, key_grip_raw);
+ if (err)
+ goto out;
+
+ key_grip_raw[sizeof (key_grip_raw) - 1] = 0;
+ ret = agent_key_available (key_grip_raw);
+ if (! ret)
+ goto out;
+
+ err = ssh_key_extract_comment (key, &comment);
+ if (err)
+ goto out;
+
+ description_length = 95 + (comment ? strlen (comment) : 0);
+ description = malloc (description_length);
+ if (! description)
+ {
+ err = gpg_err_code_from_errno (errno);
+ goto out;
+ }
+ else
+ sprintf (description,
+ "Please provide the passphrase, which should be used "
+ "for protecting the received secret key `%s':",
+ comment ? comment : "");
+
+ err = get_passphrase (description, sizeof (passphrase), passphrase);
+ if (err)
+ goto out;
+
+ err = ssh_key_to_buffer (key, passphrase, &buffer, &buffer_n);
+ if (err)
+ goto out;
+
+ err = agent_write_private_key (key_grip_raw, buffer, buffer_n, 0);
+ if (err)
+ goto out;
+
+ err = agent_put_cache (key_grip_raw, passphrase, ttl);
+ if (err)
+ goto out;
+
+ out:
+
+ xfree (buffer);
+ xfree (comment);
+ xfree (description);
+ /* FIXME: verify xfree vs free. */
+
+ return err;
+}
+
+static gpg_error_t
+ssh_identity_drop (gcry_sexp_t key)
+{
+ unsigned char key_grip[21] = { 0 };
+ gpg_error_t err;
+
+ err = ssh_key_grip (key, key_grip);
+ if (err)
+ goto out;
+
+ key_grip[sizeof (key_grip) - 1] = 0;
+
+ /* FIXME: What to do here - forgetting the passphrase or deleting
+ the key from key cache? */
+
+ if (DBG_COMMAND)
+ log_debug ("[ssh-agent] dropping identity `%s'\n", key_grip);
+
+ out:
+
+ return err;
+}
+
+static int
+ssh_handler_add_identity (ctrl_t ctrl, estream_t request, estream_t response)
+{
+ gpg_error_t err;
+ gcry_sexp_t key;
+ byte_t b;
+ int confirm;
+ int death;
+ int bad;
+
+ if (DBG_COMMAND)
+ log_debug ("[ssh-agent] add identity\n");
+
+ confirm = 0;
+ death = 0;
+ key = NULL;
+ bad = 0;
+
+ /* FIXME? */
+ err = ssh_receive_key (request, &key, 1, 1, NULL);
+ if (err)
+ {
+ bad = 1;
+ goto out;
+ }
+
+ while (1)
+ {
+ err = es_read_byte (request, &b);
+ if (gpg_err_code (err) == GPG_ERR_EOF)
+ {
+ err = 0;
+ break;
+ }
+
+ switch (b)
+ {
+ case SSH_OPT_CONSTRAIN_LIFETIME:
+ {
+ uint32_t n = 0;
+
+ err = es_read_uint32 (request, &n);
+ if (! err)
+ death = time (NULL) + n;
+ break;
+ }
+
+ case SSH_OPT_CONSTRAIN_CONFIRM:
+ {
+ confirm = 1;
+ break;
+ }
+
+ default:
+ /* FIXME: log/bad? */
+ break;
+ }
+ }
+ if (err)
+ goto out;
+
+ if (lifetime_default && (! death))
+ death = time (NULL) + lifetime_default;
+
+ /* FIXME: are constraints used correctly? */
+
+ err = ssh_identity_register (key, death);
+
+ out:
+
+ gcry_sexp_release (key);
+
+ if (! bad)
+ es_write_byte (response, err ? SSH_RESPONSE_FAILURE : SSH_RESPONSE_SUCCESS);
+
+ return bad;
+}
+
+static int
+ssh_handler_remove_identity (ctrl_t ctrl, estream_t request, estream_t response)
+{
+ unsigned char *key_blob;
+ uint32_t key_blob_size;
+ gcry_sexp_t key;
+ gpg_error_t err;
+ int bad;
+
+ /* Receive key. */
+
+ if (DBG_COMMAND)
+ log_debug ("[ssh-agent] remove identity\n");
+
+ key_blob = NULL;
+ key = NULL;
+ bad = 0;
+
+ err = es_read_string (request, 0, &key_blob, &key_blob_size);
+ if (err)
+ {
+ bad = 1;
+ goto out;
+ }
+
+ err = ssh_read_key_public_from_blob (key_blob, key_blob_size, &key, NULL);
+ if (err)
+ {
+ bad = 1;
+ goto out;
+ }
+
+ err = ssh_identity_drop (key);
+
+ out:
+
+ xfree (key_blob);
+ gcry_sexp_release (key);
+
+ if (! bad)
+ es_write_byte (response, err ? SSH_RESPONSE_FAILURE : SSH_RESPONSE_SUCCESS);
+
+ return bad;
+}
+
+static gpg_error_t
+ssh_identities_remove_all (void)
+{
+ gpg_error_t err;
+
+ if (DBG_COMMAND)
+ log_debug ("[ssh-agent] remove all identities\n");
+
+ err = 0;
+
+ /* FIXME: shall we remove _all_ cache entries or only those
+ registered through the ssh emulation? */
+
+ return err;
+}
+
+static int
+ssh_handler_remove_all_identities (ctrl_t ctrl, estream_t request, estream_t response)
+{
+ gpg_error_t err;
+
+ err = ssh_identities_remove_all ();
+ es_write_byte (response, err ? SSH_RESPONSE_FAILURE : SSH_RESPONSE_SUCCESS);
+
+ return 0;
+}
+
+static gpg_error_t
+ssh_lock (void)
+{
+ gpg_error_t err;
+
+ if (DBG_COMMAND)
+ log_debug ("[ssh-agent] lock\n");
+
+ err = 0;
+
+ return err;
+}
+
+static gpg_error_t
+ssh_unlock (void)
+{
+ gpg_error_t err;
+
+ if (DBG_COMMAND)
+ log_debug ("[ssh-agent] unlock\n");
+
+ err = 0;
+
+ return err;
+}
+
+static int
+ssh_handler_lock (ctrl_t ctrl, estream_t request, estream_t response)
+{
+ gpg_error_t err;
+
+ err = ssh_lock ();
+ es_write_byte (response, err ? SSH_RESPONSE_FAILURE : SSH_RESPONSE_SUCCESS);
+
+ return 0;
+}
+
+static int
+ssh_handler_unlock (ctrl_t ctrl, estream_t request, estream_t response)
+{
+ gpg_error_t err;
+
+ err = ssh_unlock ();
+ es_write_byte (response, err ? SSH_RESPONSE_FAILURE : SSH_RESPONSE_SUCCESS);
+
+ return 0;
+}
+
+
+
+/* Associating request types with the corresponding request
+ handlers. */
+
+static ssh_request_spec_t request_specs[] =
+ {
+ { SSH_REQUEST_REQUEST_IDENTITIES, ssh_handler_request_identities },
+ { SSH_REQUEST_SIGN_REQUEST, ssh_handler_sign_request },
+ { SSH_REQUEST_ADD_IDENTITY, ssh_handler_add_identity },
+ { SSH_REQUEST_ADD_ID_CONSTRAINED, ssh_handler_add_identity },
+ { SSH_REQUEST_REMOVE_IDENTITY, ssh_handler_remove_identity },
+ { SSH_REQUEST_REMOVE_ALL_IDENTITIES, ssh_handler_remove_all_identities },
+ { SSH_REQUEST_LOCK, ssh_handler_lock },
+ { SSH_REQUEST_UNLOCK, ssh_handler_unlock },
+ };
+
+
+
+static gpg_error_t
+ssh_request_process (ctrl_t ctrl, estream_t request, estream_t response)
+{
+ byte_t request_type;
+ gpg_error_t err;
+ unsigned int i;
+ int bad;
+
+ err = es_read_byte (request, &request_type);
+ if (err)
+ goto out;
+
+ if (DBG_COMMAND)
+ log_debug ("[ssh-agent] request: %u\n", request_type);
+
+ for (i = 0; i < DIM (request_specs); i++)
+ if (request_specs[i].type == request_type)
+ break;
+ if (i == DIM (request_specs))
+ {
+ err = es_write_byte (response, SSH_RESPONSE_FAILURE);
+ goto out;
+ }
+
+
+ bad = (*request_specs[i].handler) (ctrl, request, response);
+ if (bad)
+ err = GPG_ERR_PROTOCOL_VIOLATION;
+
+ out:
+
+ return err;
+}
+
+void
+start_command_handler_ssh (int sock_client)
+{
+ struct server_control_s ctrl;
+ gpg_error_t err;
+ estream_t stream_response;
+ estream_t stream_request;
+ estream_t stream_sock;
+ unsigned char *request;
+ uint32_t request_size;
+ size_t size;
+ int ret;
+
+ /* Setup control structure. */
+
+ if (DBG_COMMAND)
+ log_debug ("[ssh-agent] Starting command handler\n");
+
+ memset (&ctrl, 0, sizeof (ctrl));
+ ctrl.connection_fd = sock_client;
+
+ stream_response = NULL;
+ stream_request = NULL;
+ stream_sock = NULL;
+ request = NULL;
+
+ stream_sock = es_fdopen (sock_client, "r+");
+ if (! stream_sock)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+ ret = es_setvbuf (stream_sock, NULL, _IONBF, 0);
+ if (ret)
+ {
+ err = gpg_error_from_errno (errno);
+ goto out;
+ }
+
+ while (1)
+ {
+ /* Create memory streams for request/response data. The entire
+ request will be stored in secure memory, since it might
+ contain secret key material. The response does not have to
+ be stored in secure memory, since we never give out secret
+ keys. FIXME: wrong place. */
+
+ /* Retrieve request. */
+ err = es_read_string (stream_sock, 1, &request, &request_size);
+ if (err)
+ break;
+
+ if (DBG_COMMAND)
+ log_debug ("[ssh-agent] Received request of length: %u\n",
+ request_size);
+
+ stream_request = es_mopen (NULL, 0, 0, 1,
+ realloc_secure, gcry_free, "r+");
+ if (! stream_request)
+ {
+ err = gpg_error_from_errno (errno);
+ break;
+ }
+ ret = es_setvbuf (stream_request, NULL, _IONBF, 0);
+ if (ret)
+ {
+ err = gpg_error_from_errno (errno);
+ break;
+ }
+ err = es_write_data (stream_request, request, request_size);
+ if (err)
+ break;
+ es_rewind (stream_request);
+
+ stream_response = es_mopen (NULL, 0, 0, 1, NULL, NULL, "r+");
+ if (! stream_response)
+ {
+ err = gpg_error_from_errno (errno);
+ break;
+ }
+
+ /* Process request. */
+ err = ssh_request_process (&ctrl, stream_request, stream_response);
+ if (err)
+ break;
+
+ /* Figure out size of response data. */
+ size = es_ftell (stream_response);
+ err = es_fseek (stream_response, 0, SEEK_SET);
+ if (err)
+ break;
+
+ /* Write response data to socket stream. */
+ err = es_write_uint32 (stream_sock, size);
+ if (err)
+ break;
+ err = es_copy (stream_sock, stream_response);
+ if (err)
+ break;
+
+ err = es_fflush (stream_sock);
+ if (err)
+ break;
+
+ es_fclose (stream_request);
+ stream_request = NULL;
+ es_fclose (stream_response);
+ stream_response = NULL;
+ xfree (request);
+ request = NULL;
+ };
+
+ out:
+
+ /* FIXME: logging. */
+
+ if (stream_sock)
+ es_fclose (stream_sock);
+ if (stream_request)
+ es_fclose (stream_request);
+ if (stream_response)
+ es_fclose (stream_response);
+ xfree (request); /* FIXME? */
+
+ if (DBG_COMMAND)
+ log_debug ("[ssh-agent] Leaving ssh command handler: %s\n", gpg_strerror (err));
+}
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